1. Field of the Invention
The present invention relates to a wireless communication apparatus, such as a cellular phone, etc.
2. Description of the Related Art
In a wireless communication apparatus such as a portable terminal, the miniaturization is demanded for the improvement of a portability and a reduction of an arrangement area. On the other hand, it is demanded to reduce a noise to the wireless communication apparatus. However, a requirement of structure of cases and parts for size reduction and a requirement of structure of cases and parts for noise reduction are not met.
For instance, recently, a cellular phone, which has a first case, a second case and a hinge part connecting the first case and the second case to allow the rotation of them and enabling to be opened and closed, is widely used. In the cellular phone, the miniaturization when the user carries it is attempted by composing the both cases to be openable and closable. However, in such a cellular phone, antenna characteristics may change between in an opened state and in a closed state because the position of the one case provided with an antenna and the other case changes between when opening and closing the terminal. Therefore, it is difficult to improve the antenna gain in the both of the opened state and the closed state. In other words, it is difficult to achieve the reduction of the noise to the signal.
Moreover, for instance, a cellular phone having a shield for shielding the noise in the case has been known. However, the shield has bulky size. Therefore, the arrangement of the shield, etc. adversely affects the miniaturization of the wireless communication apparatus.
As a countermeasure for overcoming the disadvantage that the antenna characteristics are changed when opened and when closed the cases, a walkie-talkie machine has been proposed (JP 2003-101623 A (2003)). The walkie-talkie machine has a first antenna arranged in a first case, a second antenna arranged in a second case, and a switching part switching between the first antenna and the second antenna according to the state of an open or close of the terminal as the antenna used for communication. Further, a technology for arranging an antenna inside a walkie-talkie machine is proposed, but it does not show countermeasures to overcome the disadvantage that the antenna characteristics are changed (JP 10-163748 A (1996), JP 11-312912 A (1999)).
Moreover, as a technology concerning the miniaturization of the terminal having the shield, a technology that uses a shielding case as a reinforcement member of the battery is proposed (JP 2002-261894 A (2002)).
In JP 2003-101623 A, the reduction of the antenna gain because of the change of the state of the case: opened or closed, is supplemented between the first antenna and the second antenna, to prevent the reduction of the transmission and reception efficiency. But it does not disclose the technology that prevents the reduction of the antenna gain.
In JP 2002-261894 A, the shield is used as a reinforcement member in addition to the shield member, and thus the case is miniaturized only by the size that corresponds to the reinforcement member. But the above technology does not disclose that the shield is used for the arrangement of the other parts.
It is an object of the present invention to provide an wireless communication apparatus that a freedom of the design relating to miniaturization thereof can be improved together with the noise reduction.